Golf balls incorporating light-stable and durable cover compositions
View Patent ↗A golf ball comprising: a core; a casing layer surrounding the core; and a cover layer surrounding the casing layer and being formed from a cover composition that is produced by a reaction of a prepolymer and a chain extender, wherein the prepolymer is formed from the reaction product of: (i) an isocyanate comprising an allophanate (“ICA”) and having an average NCO functionality in the range of 1.9 to 2.8 and (ii) a polyol-containing component or an amine-containing component or a blend thereof; and wherein the chain-extender is selected from the group consisting of amine-terminated chain-extenders, hydroxyl-terminated chain-extenders, and mixtures thereof. The ICA may comprise a reaction product of hexamethylene diisocyanate (HDI), at least one monoalcohol, and a bismuth-containing catalyst. The ICA may have an average equivalent weight of from about 200 to about 350; and the prepolymer may have an average equivalent weight of from about 420 to about 840. The cover has a thickness of at least about 0.010 in. and a flexural modulus of about 10,000 psi or greater.
1. A golf ball comprising:
a core;
a casing layer surrounding the core; and
a cover layer surrounding the casing layer and being formed from cover composition PC that is produced by a reaction of a prepolymer and a chain extender, wherein the prepolymer is formed from the reaction product of: (i) an isocyanate comprising an allophanate (“ICA”) and having an average NCO functionality in the range of 1.9 to 2.8 and (ii) a polyol-containing component; and
wherein the chain-extender is selected from the group consisting of amine-terminated chain-extenders, hydroxyl-terminated chain-extenders, and mixtures thereof; and wherein the ICA is reacted with the polyol-containing component and chain-extender in a weight ratio of about 1.9:1; and
wherein the polyol-containing component and chain-extender are included in cover composition PC in a weight ratio of about 1.3:1.
2. The golf ball of claim 1 , wherein the isocyanate comprises a reaction product of hexamethylene diisocyanate (HDI), at least one monoalcohol, and a bismuth-containing catalyst.
3. The golf ball of claim 2 , wherein the monoalcohol is selected from the group consisting of: ethoxylated C 12 -C 14 alcohols, ethoxylated C 16 -C 18 alcohols, and ethoxylated C 10 -C 16 alcohols.
4. The golf ball of claim 1 , wherein the core has a surface hardness H of from about 50 Shore C to about 90 Shore C and a center hardness CH of from about 50 Shore C to about 90 Shore C, the casing layer has a surface hardness A of from about 45 Shore D to about 80 Shore D, and the cover has a hardness B of from about 65 Shore C to about 90 Shore C.
5. The golf ball of claim 4 , wherein H is greater than CH.
6. The golf ball of claim 4 , wherein H is less than CH.
7. The golf ball of claim 4 , wherein H is substantially similar to CH.
8. The golf ball of claim 1 , having a compression of from about 40 to about 120.
9. The golf ball of claim 1 , wherein the ICA has an average equivalent weight of from about 200 to about 350.
10. The golf ball of claim 1 , wherein the ICA has an average equivalent weight of from about 320 to about 330.
11. The golf ball of claim 1 , wherein the prepolymer has an average equivalent weight of from about 420 to about 840.
12. The golf ball of claim 1 , wherein the amine-terminated chain extender is selected from the group consisting of 4,4′-diamino-diphenylmethane; 3,5-diethyl-(2,4- or 2,6-) toluenediamine; 3,5-dimethylthio-(2,4- or 2,6-)toluenediamine; 3,5-diethylthio-(2,4- or 2,6-) toluenediamine: 2,2′-dichloro-3,3′,5,5′-tetraethyl-4,4′-diamino-diphenylmethane; polytetramethyleneglycol-di(p-aminobenzoate); 4,4′-bis(sec-butylamino)-dicyclohexylmethane; and mixtures thereof.
13. The golf ball of claim 1 , wherein the hydroxyl-terminated chain-extender is selected from the group consisting of ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polytetramethylene ether glycol, polyethylene propylene glycol, polyoxypropylene glycol, 2-methyl-1,3-propanediol, 1,4-butanediol, 2-methyl-1,4-butanediol, and mixtures thereof.
14. The golf ball of claim 1 , wherein the core comprises a center and an outer core layer surrounding the center, wherein the center is formed from a polybutadiene composition and the outer core layer is formed from a thermoplastic composition selected from the group consisting of: ionomers; polyesters; polyester-ether elastomers; polyester-ester elastomers; polyamides; polyamide-ether elastomers, and polyamide-ester elastomers; polyurethanes, polyureas, and polyurethane-polyurea hybrids and mixtures thereof.
15. The golf ball of claim 1 , wherein the core comprises a center and an outer core layer surrounding the center, wherein the center is formed from a polybutadiene composition and the outer core layer is formed from a thermoset composition selected from the group consisting of: polyurethanes, polyureas, and polyurethane-polyurea hybrids, epoxies, and mixtures thereof.
16. The golf ball of claim 1 , wherein the core has a diameter of about 1.26 to about 1.60 inches.
17. The golf ball of claim 1 , wherein the cover has a thickness of from about 0.020 in. to about 0.050 in.
18. The golf ball of claim 17 , wherein the cover has a flexural modulus of about 10,000 psi or greater.
19. The golf ball of claim 1 , wherein the ICA is reacted with the polyol-containing component and chain-extender in a weight ratio of 1.878:1.
20. The golf ball of claim 19 , wherein the polyol-containing component and chain-extender are included in cover composition PC in a weight ratio of 1.265:1.